Chip with simple program for Toy

Anthony Fremont · Jan 24, 2005

"keith" <krw@att.bizzzz> wrote

I disagree. In the grand scheme of a signal that's usually taking
tens
of mS to make its journey, a few uS of turnaround overhead is not,
IMO,
significant nor does it have to be an unknown.

We're talking abotu cars a few tens of feet apart. Thus it's
nanoseconds,
and *any* turn-around in the transponder is *significant*.

Mac originally wrote:

Ultrasound might work well. You could have a transponder on the back
of the car in front and a range-finder on the front of the car in
back.

This portion of the thread is about using ultrasound transponders, not
radar or IR. Sound doesn't get very far in a nS.

Robert Monsen · Jan 24, 2005

Ken Smith wrote:

In article <pan.2005.01.22.09.23.03.387634@example.net>,
Rich Grise <richgrise@example.net> wrote:
[...]

People have mentioned triangulation. Does a license plate retroreflect
laser pointer light?

Why not just image the plate with a camera and measure the image size with
software? When the cars get further apart the image of the plate gets
smaller. No LEDs needed.

That is a pretty good idea. I'm not sure it's workable as is, though.

A license plate is a foot across. Thus, the function of angle given
distance is

f(x) = 2*arcsin(.5/x)

At 50', that translates to about 0.02 radians. Not too bad. However,

f'(x) = about 1/x^2

For a change of 1 foot at 50', that would be an angular change of
1/2500. It's better at 10', where a foot change would cause 1/100 change
in angle. If the maximum width were 500 pixels, then you could detect a
foot change (ie, 1/500 = 1 pixel) at 22 feet.

However, another possibility would be to use the camera to measure the
entire car width. You could use the license plate as a standard measure,
and measure the width in license plates (which are 1 foot in width in
the US.) That way, you could use the wider angles, but also have an
absolute measure. Also, that way you could autozoom the camera without
losing registration, and get better angular resolution for longer distances.

One problem is that license plates change colors, so identification
might be an issue. Thankfully, they are almost always in the same place
on the vehicle.

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

Rich Grise · Jan 24, 2005

On Sun, 23 Jan 2005 23:20:28 -0500, Dave VanHorn wrote:

For a change of 1 foot at 50', that would be an angular change of
1/2500. It's better at 10', where a foot change would cause 1/100 change
in angle. If the maximum width were 500 pixels, then you could detect a
foot change (ie, 1/500 = 1 pixel) at 22 feet.

Well, the good news is that as it becomes more important, it becomes easier
to see the difference.

I wonder what the original intent was. Does the OP want to have a machine
to substitute for paying attention to the road? To decide on a safe
following distance for him? Is this the next stage in "Cruise Control?"

If you're looking for the distance to a specific car, or relative speed,
then take a spring-loaded reel of wire, or string, and attach the end to
the car in front, then sense the position/speed of the tether wire.

What's the actual goal here?

If he wants to drive a car without driving a car, then he should either
take cabs or just drive off a bridge.

Thanks,
Rich

Dave VanHorn · Jan 24, 2005

I wonder what the original intent was. Does the OP want to have a machine
to substitute for paying attention to the road? To decide on a safe
following distance for him? Is this the next stage in "Cruise Control?"

It is in fact the next thing in cruise control.
The current ones are blind, and will not compensate for changes in the speed
of the car you're following. There are a few systems out now, that handle
that, plus braking if they sense rapid downward change in separation. The
theory is that they can react faster than you do.

Robert Monsen · Jan 24, 2005

gaurav.patil@gmail.com wrote:

hello,
i want to construct a circuit which will be able to measure distance
between two moving cars.The two cars are needed to maintain a fixed
distance between each other.
if the distance between them increases or decreases the circuit
should be able to detect this change and notify the amount of change
in the distance to both cars.
i want to construct this circuit using infrared LEDS ,so if any one
can help me out with this(circuit idea) please mail it to me .

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=73916&item=7129299161&rd=1&tc=photo

Mount it on your car so it fires directly forward. Hack the output
section so it gives a signal which can be fed into your cruise control...

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

Mac · Jan 25, 2005

On Sun, 23 Jan 2005 22:59:46 -0500, keith wrote:

On Mon, 24 Jan 2005 00:09:10 +0000, Mac wrote:

On Sun, 23 Jan 2005 14:07:55 -0500, keith wrote:

On Sun, 23 Jan 2005 17:51:45 +0000, Mac wrote:

On Sat, 22 Jan 2005 23:41:45 -0500, keith wrote:

On Sat, 22 Jan 2005 07:32:19 +0000, Mac wrote:

On Fri, 21 Jan 2005 04:24:38 -0800, Andrew Holme wrote:

gaurav.patil@gmail.com wrote:
hello,
i want to construct a circuit which will be able to measure distance
between two moving cars.The two cars are needed to maintain a fixed
distance between each other.
if the distance between them increases or decreases the circuit
should be able to detect this change and notify the amount of change
in the distance to both cars.
i want to construct this circuit using infrared LEDS ,so if any one
can help me out with this(circuit idea) please mail it to me .

It might be easier with microwaves than infra-red:

Measure relative velocity using the Doppler effect. By integrating
this, you get a running estimate of the change in distance. Weird
things might happen when you go around corners!

Unfortunately, absolute measurement of short distances using
electromagnetic waves is difficult / impossible due to the speed of
light.

It is not difficult at all. It just requires bandwidth. Before anybody
jumps on my case about detecting short CW pulses, let me point out that
short CW pulses have a LOT of bandwidth, and the shorter they are the more
bandwidth they have.

Ok, what's the bandwidth of a kHz modulated ~2GHz carrier (wherever there
is some free bandwidth). It should be trivial to measure the round-trip
delay to withing a nS, which is about six inches. At a kHz,
that gives us a distance measuremnt every millisecond, which should be
enough for distance and differentiate to give a relative velocity
number.

Are you talking about on/off modulation of a 2GHz carrier at a 1KHz
rate? How long is the "on" time?

Yes, pick your poision.

It looks like it doesn't really matter, anyway. The Fourier transform is
just a sum of two sinc() functions, one shifted right and one shifted left
by the carrier frequency. The pulse duration controls the magnitude of the
FT.

Sure. I'm looking at launching a ~2GHz (wherever the FCC allows) CW pulse
and measuring its time in flight. At a ns/ft that's 6"/ns round-trip.
Some tricks should be able to get this down significantly less than this.
A ns is a long time these days.

I believe the total bandwidth is infinite, but any finite signal
has infinite bandwidth, so that doesn't really help us.

Sure. I don't see a few kHz on either side of 2GHz to be a big deal
though. It might be a challenge to gate an uwave tranmsitter on in a
millisecond, but...

It is not difficult to turn on a low power transmitter in a millisecond.
But I don't think a few kHz of bandwidth is anywhere near enough. I was
too busy today to talk this over with people who would know.

Unfortunately, I'm not sure I know how to answer the question myself.

I'll try to remember to ask some people who might know tomorrow and get
back to you. (It also might pay to ask in the radar/sonar newsgroup.)

RADAR was my primary interest here. Measuring ns delays is rather trivial
these days. ...and that gets us to 6" distance resolution. Put enough of
these together with a (very) little computation and we get velocity. I
don't see how the mechanics of a couple of cars will exceed the physics or
computational needs.

Well, measuring a ns delay can be somewhat challenging in a digital
circuit. It is easy for a good oscilloscope, of course. But even if you
use an ADC, followed by a DSP, the ns resolution implies a sample rate of
1 GHz, in some sense.

I have seen programmable delay circuits which were adjustable in
small steps (picoseconds) but they incorporated clever analog stuff
along with digital clocks.

In the application you are talking about, you would need to have some kind
of analog detection (time to voltage circuit, perhaps) which would then be
sampled.

But the more you constrain the bandwidth, the more difficult it will be
to identify exactly where the pulse starts or stops. So for precise
ranging, you need more BW, regardless of pulse duration.

Ok. We can measure more points of the envelope. The question is where is
the bandwidth limitation. I suspect it will be in the transmitter,
though I don't know. Again, a few kHz isn't a lot of bandwidth.

Well, the transmitter doesn't have to be high bandwidth. You just need a
high bandwidth (fast) switch between it and the antenna. The antenna does
need to have high bandwidth.

The receive chain, including the antenna, I think, does need to be
wideband. That opens you up to all kinds of noise, which is
problematic. I'm not saying its impossible, I'm just saying that it isn't
trivial or easy.

Another problem with 2GHz is that it is difficult to get a narrow beam
antenna that can fit unobtrusively into the car's styling.

[snip]

Ultrasound might work well. You could have a transponder on the back
of the car in front and a range-finder on the front of the car in
back.

It's *is* done without any transponder, which would make the idea
useless.

I admit that the transponder is not essential. It just makes it easier
to detect the signal, and increases the range over which the system
would work.

It also adds an unknown and significant delay into the path.

Depending on exactly how the system is set up, the delay could be
completely neutralized by using a PLL.

How? The PLL has to capture the signal and then re-launch the "answer".
That's time. If we're measuring the round-trip delay of two cars ten
meters apart on the Autobahn, the capture/retransmit time is an error I'd
rather not make.

You could use a dual frequency scheme where you send out a pulse
at f1, during which the PLL can lock, then abruptly change the
frequency to f2. As soon as the transponder PLL detects the step
in frequency, it can turn on its transmit gate.

The transmitter would use the frequency step as the synchronizing time. I
don't know that this would work it is just a thought.

--Mac

Mark Jones · Jan 25, 2005

Dave VanHorn wrote:

I wonder what the original intent was. Does the OP want to have a machine
to substitute for paying attention to the road? To decide on a safe
following distance for him? Is this the next stage in "Cruise Control?"

It is in fact the next thing in cruise control.
The current ones are blind, and will not compensate for changes in the speed
of the car you're following. There are a few systems out now, that handle
that, plus braking if they sense rapid downward change in separation. The
theory is that they can react faster than you do.

React faster, probably. React better? No way. Unless this idea is
*very* well engineered, it will likely backfire with catastrophic
results. There are an infantessimal number of anomalous things that
can happen while a vehicle is in motion. Anything from equipment
failures to weather conditions, obstacles in the road, visibility
issues, even radiological accidents, etc... a human really is needed
to process all of that information during driving (and even so,
sometimes we get it wrong.) A device to further refine "cruise
control" likely needs to be more A.I. than hardware. For instance, if
you were cruising down the highway and the distance-to-car-in-front
sensor suddenly malfunctioned and indicated you were 0 feet from the
car in front of you and travelling at 70MPH, what would happen? Would
that in itself cause an accident? No per-vehicle cruise control system
could accomidate that kind of an issue. But if the cars were connected
to an A.I. network...

-- "It is said that a caterpillar must struggle to open it's own
cocoon. It is this struggle which makes it strong enough to survive
being a butterfly. If a person were to help the caterpillar open it's
cocoon, the butterfly will die." MCJ 20050119

John Woodgate · Jan 25, 2005

I read in sci.electronics.design that Rich Grise <richgrise@example.net>
wrote (in <pan.2005.01.25.21.22.10.964716@example.net&gt

about 'Car A.I.
[was: measuring distance between two cars using infrared circuits]', on
Tue, 25 Jan 2005:

How do those supermarket door openers work? (not the footpad - the ones
with the little box over the door)

I've always supposed they work the same as a security light, using a
pyroelectric ceramic.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

Jim Thompson · Jan 25, 2005

On Tue, 25 Jan 2005 21:35:08 +0000, John Woodgate
<jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that Rich Grise <richgrise@example.net
wrote (in <pan.2005.01.25.21.22.10.964716@example.net&gt about 'Car A.I.
[was: measuring distance between two cars using infrared circuits]', on
Tue, 25 Jan 2005:

How do those supermarket door openers work? (not the footpad - the ones
with the little box over the door)

I've always supposed they work the same as a security light, using a
pyroelectric ceramic.

480)460-2350 | |
| E-mail Address at Website Fax

Mac · Jan 26, 2005

On Sun, 23 Jan 2005 22:59:46 -0500, keith wrote:

On Mon, 24 Jan 2005 00:09:10 +0000, Mac wrote:

On Sun, 23 Jan 2005 14:07:55 -0500, keith wrote:

On Sun, 23 Jan 2005 17:51:45 +0000, Mac wrote:

On Sat, 22 Jan 2005 23:41:45 -0500, keith wrote:

[snip]

Ok, what's the bandwidth of a kHz modulated ~2GHz carrier (wherever there
is some free bandwidth). It should be trivial to measure the round-trip
delay to withing a nS, which is about six inches. At a kHz,
that gives us a distance measuremnt every millisecond, which should be
enough for distance and differentiate to give a relative velocity
number.

Are you talking about on/off modulation of a 2GHz carrier at a 1KHz
rate? How long is the "on" time?

Yes, pick your poision.

It looks like it doesn't really matter, anyway. The Fourier transform is
just a sum of two sinc() functions, one shifted right and one shifted left
by the carrier frequency. The pulse duration controls the magnitude of the
FT.

Sure. I'm looking at launching a ~2GHz (wherever the FCC allows) CW pulse
and measuring its time in flight. At a ns/ft that's 6"/ns round-trip.
Some tricks should be able to get this down significantly less than this.
A ns is a long time these days.

I believe the total bandwidth is infinite, but any finite signal
has infinite bandwidth, so that doesn't really help us.

Sure. I don't see a few kHz on either side of 2GHz to be a big deal
though. It might be a challenge to gate an uwave tranmsitter on in a
millisecond, but...

Unfortunately, I'm not sure I know how to answer the question myself.

I'll try to remember to ask some people who might know tomorrow and get
back to you. (It also might pay to ask in the radar/sonar newsgroup.)

RADAR was my primary interest here. Measuring ns delays is rather trivial
these days. ...and that gets us to 6" distance resolution. Put enough of
these together with a (very) little computation and we get velocity. I
don't see how the mechanics of a couple of cars will exceed the physics or
computational needs.

But the more you constrain the bandwidth, the more difficult it will be
to identify exactly where the pulse starts or stops. So for precise
ranging, you need more BW, regardless of pulse duration.

Ok. We can measure more points of the envelope. The question is where is
the bandwidth limitation. I suspect it will be in the transmitter,
though I don't know. Again, a few kHz isn't a lot of bandwidth.

I talked to one of my co-workers today, and he said that as a very rough
order of magnitude estimate, the receive bandwidth needs to be about 1/T,
where T is the pulse duration. So if you want a 10 ns pulse, you will need
on the order of 100 MHz of receive bandwidth.

The situation is somewhat analogous to sending a digital pulse through a
bandwidth-constrained channel (filter). Depending on the nature of the
filter, it may ring or just ramp up slowly.

If the bandwidth is too narrow, you may not see the pulse at all.

There are other practical problems to overcome.Some of the other practical
problems with this system are that unless the beam width is kept narrow,
strong returns from objects on the side of the road will swamp the
receiver.

Anyway, it is fun to think about it.

--Mac

Paul Hovnanian P.E. · Jan 26, 2005

peterken wrote:

"Andrew Holme" <ajholme@hotmail.com> wrote in message
news:1106310278.349514.124760@z14g2000cwz.googlegroups.com...

gaurav.patil@gmail.com wrote:
hello,
i want to construct a circuit which will be able to measure distance
between two moving cars.The two cars are needed to maintain a fixed
distance between each other.
if the distance between them increases or decreases the circuit
should be able to detect this change and notify the amount of change
in the distance to both cars.
i want to construct this circuit using infrared LEDS ,so if any one
can help me out with this(circuit idea) please mail it to me .

It might be easier with microwaves than infra-red:

Measure relative velocity using the Doppler effect. By integrating
this, you get a running estimate of the change in distance. Weird
things might happen when you go around corners!

Unfortunately, absolute measurement of short distances using
electromagnetic waves is difficult / impossible due to the speed of
light.

microwave is indeed more reliable
using a bursting microwave gives an indication of absolute distance and
speed between objects

timing between start of burst and start of reception of it is a measure for
absolute distance
doppler frequency gives relative speed

Modulate the microwave pulse frequency. There are modulation schemes (a
quick ramp up in frequency, or chirp for example) that will allow the
detection of both range and speed from the reflected signal. The DSP
might get a little more expensive than what is needed for Doppler alone.

--
Paul Hovnanian mailto

aul@Hovnanian.com
------------------------------------------------------------------
If you can't beat them, arrange to have them beaten.
-- George Carlin

Robert Monsen · Jan 26, 2005

Rich Grise wrote:

On Tue, 25 Jan 2005 14:46:23 -0800, Robert Monsen wrote:

Aaron Hughes wrote:

Typically when you write to a flash chip, you MUST write to the entire
sector (128 bytes usually) within a specified window. These bytes are
written into a buffer on the chip, and only if you are within the window
time, does the chip *itself* write the bytes. Hence, if you only write
ONE byte, the other 127 in that sector are reset to FFh. Thus if you
expect ot write one byte, wait a while, then another byte etc, only 1 of
your valid data bytes will ever be present in the sector, all other
bytes will be FFh.

I'm familiar with Atmel flash, and it doesn't all work this way. You can
write a single byte with 'large sector' flash. It's only the small sector
flash that requires one to write an entire sector.

http://www.atmel.com/dyn/resources/prod_documents/doc1026.pdf

see the description. This is a 64kb flash. There are larger ones (I've
used the 4Mb version before) that are the same as this one.

I beg to differ. According to the data sheet, "ERASURE: Before a byte
can be reprogrammed, the 64K bytes memory array must be erased."

The statement I was objecting to was that one needs to write an entire
sector at once. This is false for 'large sector' flash, as in the
datasheet. However, there ARE some flashes, the 'small sector' flashes,
that require one to write an entire small sector of 128 bytes at once.

A flash write (for large sector flash) works by setting bits to 0. They
all start out at 1, and you set them to zero using the write sequence.
Once they are set to 0, you can't set them back to 1 without erasing the
entire sector.

So I can't really see using it for nonvolatile data storage, unless you
just keep writing until it's full, then download it all and erase the
thing.

That's what we do. For example, I've used flash for log files before.
One uses two or more sectors. That way, you only have to erase part of
your log when circling back to the start.

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

Keith Williams · Jan 26, 2005

In article <pan.2005.01.26.04.29.45.81430@bar.net>, foo@bar.net says...

On Sun, 23 Jan 2005 22:59:46 -0500, keith wrote:

On Mon, 24 Jan 2005 00:09:10 +0000, Mac wrote:

On Sun, 23 Jan 2005 14:07:55 -0500, keith wrote:

On Sun, 23 Jan 2005 17:51:45 +0000, Mac wrote:

On Sat, 22 Jan 2005 23:41:45 -0500, keith wrote:

[snip]

Ok, what's the bandwidth of a kHz modulated ~2GHz carrier (wherever there
is some free bandwidth). It should be trivial to measure the round-trip
delay to withing a nS, which is about six inches. At a kHz,
that gives us a distance measuremnt every millisecond, which should be
enough for distance and differentiate to give a relative velocity
number.

Are you talking about on/off modulation of a 2GHz carrier at a 1KHz
rate? How long is the "on" time?

Yes, pick your poision.

It looks like it doesn't really matter, anyway. The Fourier transform is
just a sum of two sinc() functions, one shifted right and one shifted left
by the carrier frequency. The pulse duration controls the magnitude of the
FT.

Sure. I'm looking at launching a ~2GHz (wherever the FCC allows) CW pulse
and measuring its time in flight. At a ns/ft that's 6"/ns round-trip.
Some tricks should be able to get this down significantly less than this.
A ns is a long time these days.

I believe the total bandwidth is infinite, but any finite signal
has infinite bandwidth, so that doesn't really help us.

Sure. I don't see a few kHz on either side of 2GHz to be a big deal
though. It might be a challenge to gate an uwave tranmsitter on in a
millisecond, but...

Unfortunately, I'm not sure I know how to answer the question myself.

I'll try to remember to ask some people who might know tomorrow and get
back to you. (It also might pay to ask in the radar/sonar newsgroup.)

RADAR was my primary interest here. Measuring ns delays is rather trivial
these days. ...and that gets us to 6" distance resolution. Put enough of
these together with a (very) little computation and we get velocity. I
don't see how the mechanics of a couple of cars will exceed the physics or
computational needs.

But the more you constrain the bandwidth, the more difficult it will be
to identify exactly where the pulse starts or stops. So for precise
ranging, you need more BW, regardless of pulse duration.

Ok. We can measure more points of the envelope. The question is where is
the bandwidth limitation. I suspect it will be in the transmitter,
though I don't know. Again, a few kHz isn't a lot of bandwidth.

I talked to one of my co-workers today, and he said that as a very rough
order of magnitude estimate, the receive bandwidth needs to be about 1/T,
where T is the pulse duration. So if you want a 10 ns pulse, you will need
on the order of 100 MHz of receive bandwidth.

Makes sense to me.

The situation is somewhat analogous to sending a digital pulse through a
bandwidth-constrained channel (filter). Depending on the nature of the
filter, it may ring or just ramp up slowly.

Sure, filters have non-zero response time. Again, makes sense. So
with a 10ns pulse one should be able to measure down to 5' without too
much trouble. One ns resolution shouldn't be all that difficult (gate
delays on the order of 10-20pS aren't all that big of a deal).

If the bandwidth is too narrow, you may not see the pulse at all.

There are other practical problems to overcome.Some of the other practical
problems with this system are that unless the beam width is kept narrow,
strong returns from objects on the side of the road will swamp the
receiver.

Look for the first return. That's the object that has the highest
probability of hitting you the soonest, thus the most "interesting".
;-).

Anyway, it is fun to think about it.

Sure. There are other issues, such as "you aren't the only one on the
road", but that's all a simple matter of engineering.

--
Keith

Paul Hovnanian P.E. · Jan 27, 2005

Dave VanHorn wrote:

How do those supermarket door openers work?
(not the footpad - the ones with the little box over the door)

Same thing, doppler microwave.
There may be some PIR units out there, but most are X or K band microwave.

Yes. Anyone with a radar detector can confirm this.

--
Paul Hovnanian mailto

aul@Hovnanian.com
------------------------------------------------------------------
Personally, I'm against people who give vent to their loquacity by
extraneous bombastic circumlocution.

Mac · Jan 27, 2005

On Tue, 25 Jan 2005 22:55:36 -0800, Paul Hovnanian P.E. wrote:

peterken wrote:

"Andrew Holme" <ajholme@hotmail.com> wrote in message
news:1106310278.349514.124760@z14g2000cwz.googlegroups.com...

gaurav.patil@gmail.com wrote:
hello,
i want to construct a circuit which will be able to measure distance
between two moving cars.The two cars are needed to maintain a fixed
distance between each other.
if the distance between them increases or decreases the circuit
should be able to detect this change and notify the amount of change
in the distance to both cars.
i want to construct this circuit using infrared LEDS ,so if any one
can help me out with this(circuit idea) please mail it to me .

It might be easier with microwaves than infra-red:

Measure relative velocity using the Doppler effect. By integrating
this, you get a running estimate of the change in distance. Weird
things might happen when you go around corners!

Unfortunately, absolute measurement of short distances using
electromagnetic waves is difficult / impossible due to the speed of
light.

microwave is indeed more reliable
using a bursting microwave gives an indication of absolute distance and
speed between objects

timing between start of burst and start of reception of it is a measure for
absolute distance
doppler frequency gives relative speed

Modulate the microwave pulse frequency. There are modulation schemes (a
quick ramp up in frequency, or chirp for example) that will allow the
detection of both range and speed from the reflected signal. The DSP
might get a little more expensive than what is needed for Doppler alone.

AIUI, the reflection from a single sweep can't give you Doppler. You would
like to keep the single sweep duration short enough so that the object
doesn't move much during the sweep.

Doppler would manifest itself over the course of several chirps as a
gradual phase shift in the IF.

If your chirp repetition rate is fast enough, you could still get very
frequent (100's of Hz) Doppler updates.

--Mac

--Mac

Paul Hovnanian P.E. · Jan 28, 2005

Dave VanHorn wrote:

AIUI, the reflection from a single sweep can't give you Doppler. You would
like to keep the single sweep duration short enough so that the object
doesn't move much during the sweep.

Chirp dosen't do doppler, it measures the distance.
So if you want rate of change of distance, you'll have to compare distances
over time.

Correct. There are some more complex modulation schemes where both
Doppler (target velocity) and distance can be derived. That's what got
me thinking about the complex DSP. But distance is what the OP wanted
anyway.

The chirp modulation ramp is selected to give a difference frequency
that is much higher than the Doppler shift created by target motion for
any reasonable distance measurement precision.

I didn't see your original post, Dave. It was in a different branch of
the thread. But great minds think alike.

--
Paul Hovnanian mailto

aul@Hovnanian.com
------------------------------------------------------------------
Real programmers don't draw flowcharts. Flowcharts are, after all, the
illiterate's form of documentation. Cavemen drew flowcharts; look how
much good it did them.

Jim Thompson · Jan 28, 2005

On Fri, 28 Jan 2005 10:39:41 +0000, Terry Pinnell
<terrypinDELETE@THESEdial.pipex.com> wrote:

I was surprised to learn today that all anti-adware and anti-spyware
programs perform so badly. Here's an extract of the ranking, from
'Anti-adware misses most malware' By Brian Livingston, in
http://windowssecrets.com/050127/

Product Adware Fixed
---------------- ------------
Giant AntiSpyware 63%
Webroot Spy Sweeper 48%
Ad-Aware SE Personal 47%
Pest Patrol 41%
SpywareStormer 35%
Intermute SpySubtract Pro 34%
PC Tools Spyware Doctor 33%
Spybot Search & Destroy 33%
McAfee AntiSpyware 33%
Xblock X-Cleaner Deluxe 31%
XoftSpy 27%
NoAdware 24%
Aluria Spyware Eliminator 23%
OmniQuad AntiSpy 16%
Spyware COP 15%
SpyHunter 15%
SpyKiller 2005 15%

So, given that there must be great overlap, I reckon my
frequently-used combination of Ad-Aware SE Personal and Spybot Search
& Destroy is catching little more than half the malware reaching me.
Unsettling.

The reviewer missed the one that seems to work quite well for me,
"Scan Spyware", but it's *paid*.

And, actually, NAV seems to be working pretty well at *identifying*
problems, but poor at removal... most adware screws with the registry
and adds DLLs, requiring booting up in SafeMode to manually clear
everything out.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice

480)460-2350 | |
| E-mail Address at Website Fax

Ken Smith · Jan 28, 2005

In article <2j5kv05pqvarkhnvn2nfu64248nl2ih6er@4ax.com>,
Terry Pinnell <terrypinDELETE@THESEdial.pipex.com> wrote:

I was surprised to learn today that all anti-adware and anti-spyware
programs perform so badly. Here's an extract of the ranking, from
'Anti-adware misses most malware' By Brian Livingston, in
http://windowssecrets.com/050127/

Product Adware Fixed
---------------- ------------
Giant AntiSpyware 63%
Webroot Spy Sweeper 48%
Ad-Aware SE Personal 47%
Pest Patrol 41%
SpywareStormer 35%
Intermute SpySubtract Pro 34%
PC Tools Spyware Doctor 33%
Spybot Search & Destroy 33%
McAfee AntiSpyware 33%
Xblock X-Cleaner Deluxe 31%
XoftSpy 27%
NoAdware 24%
Aluria Spyware Eliminator 23%
OmniQuad AntiSpy 16%
Spyware COP 15%
SpyHunter 15%
SpyKiller 2005 15%

So, given that there must be great overlap, I reckon my
frequently-used combination of Ad-Aware SE Personal and Spybot Search
& Destroy is catching little more than half the malware reaching me.
Unsettling.

It is an indication of how hard it is to remove the malware programs
without removing applications or Windows its self. There are several
things working against the writers of such software:

(1) You can't simply remove any software that appears to send data over
the network without removing portions of Windows.

(2) You can't simply remove any "strange" software since different users
have different applications installed and there is a wide variation in
what portions of Windows are installed.

(3) There is no direct way to tell the difference between a newer DLL
that has some bugs removed and one that has malware added.

I think what may be the best way to solve the problem is to place Windows
on a disk as the C drive, install all the applications from the shrink
wrapped boxes and then disconnect the write wire of the C drive. From
that point on, all the data goes on the D drive or it goes nowhere at all.

--
--
kensmith@rahul.net forging knowledge

john jardine · Jan 28, 2005

"Alex Parkinson" <ahparky@ufl.edu> wrote in message
news:ctdl17$rkg$1@spnode25.nerdc.ufl.edu...

john jardine wrote:
I've got some trash called "Cool web search" on my PC at the moment.
*Nothing* can remove the core component.
"Spybot" will crash the PC on finding it. Others just acknowledge that
this
POS is present.
Even the purpose written "CW Shredder" crashes on attempting to remove
it.

John,

There is an extra program to remove the spyware that crashes CWShredder.
You can
download it here:
http://www.spywareinfo.com/~merijn/downloads.html

Run this program, then run CWShredder and HijackThis.

Hope it helps,
Alex Parkinson

Thanks Alex.
I ran the prog and it reported No CoolWWW present. Anyway, then ran
Shredder. It found 2 CoolWWWs and removed them without crashing. Whoopee!
must be on a winner here.

Then ran Hijack-this, removed some host redirections and a couple of lost
links.
Then ran Spybot. It told me I still had 7 varieties of CoolWWW still
present. Tried to fix them but Spybot crashed out (though this time without
taking the PC with it). According to Spybot 5 CoolWWW varieties are still
active.
I'll know for sure in about 10 minutes, as the browser redirections and
other programmes and pack-mates of CoolWWW start knocking on the door.

To me it looks like CoolWWW had regenerated itself inbetween running the
progs. The guy who wrote Shredder pretty much admits it's impossible to
remove.

regards
john

Anthony Fremont · Jan 28, 2005

"john jardine" <john@jjdesigns.fsnet.co.uk> wrote in message
news:ctdnh1$rd3

Thanks Alex.
I ran the prog and it reported No CoolWWW present. Anyway, then ran
Shredder. It found 2 CoolWWWs and removed them without crashing.
Whoopee!
must be on a winner here.

Then ran Hijack-this, removed some host redirections and a couple of
lost
links.
Then ran Spybot. It told me I still had 7 varieties of CoolWWW still
present. Tried to fix them but Spybot crashed out (though this time
without
taking the PC with it). According to Spybot 5 CoolWWW varieties are
still
active.
I'll know for sure in about 10 minutes, as the browser redirections
and
other programmes and pack-mates of CoolWWW start knocking on the door.

To me it looks like CoolWWW had regenerated itself inbetween running
the
progs. The guy who wrote Shredder pretty much admits it's impossible
to
remove.

Make sure all your spyware removal programs have the latest updates
applied then unplug your network cable. You have to run the scans and
removals while not connected, otherwise stuff is being downloaded and
installed faster than you can clean it up. You may want to boot into
safe mode as well before running the removal tools.

I also suggest you try using the Microsoft Spyware Removal Tool free for
download from MS's download area. It's just a relabeled version of
Giant's product. It finds things that neither Spybot S&D nor AdAware
find. As the guy said, it's pretty much an exercise in futility trying
to totally rid your machine of all traces of this crap. You may also
need to disable windows system restore stuff so that windos doesn't help
you out by restoring the spyware infected files.

I remove allot of this junk all the time for people and the problem is
only getting worse day by day. These things engrain themselves so
deeply into windos that it's virtually impossible to get them out. I
also see allot of WTools and WebRebates on machines, this is a real bad
thing. They generally run as 2 parallel processes so terminating them
is next to impossible as the sibling will simply respawn the one you
kill. Since windos tells the process that you are trying to end task on
it to give it a chance to terminate normally, most spyware naturally
takes advantage of this as well.

Chip with simple program for Toy

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